This project will provide: 1) Preparation of enzymatically isolated myocytes from pig. Myocytes from other animals such as woodchuck, rat and mouse will also be prepared as required by the individual projects. 2) Characterization of isolated myocyte size. 3) Characterization of myocyte mechanics (contractile parameters) and intracellular Ca2+ transients. 4) Characterization of basic electrophysiological properties including action potentials and membrane currents. 5) Maintenance of equipment including three Langendorff apparatus for myocyte isolation, three video motion edge detectors, two fluorescent photomoters, and two patch-clamp recording systems. 6) Isolation of trabecular muscle.